Farm implements that employ ground-engaging tools or implements usually need the ability to raise and lower the tools and in some circumstances require a down pressure when in a ground-engaging position so that the tool or implement can move in a constant or relative position to the ground with respect to the contour of the ground surface either on the surface or at a desired depth.
When the tools or implements include a ground penetrating work piece, it is also desirable for the tool or implement to be protected so that if the tool or implement strikes an obstacle such as a rock that may or may not be completely covered by the contour of the ground, the tool or implement can move against the downward pressure or weight of the machine frame in and upward manner to clear the obstacle without damaging the tool or implement.